If you're planning a bit of sightseeing during your trip, head to Casemates Square— just one of the monuments in central Gibraltar. Hotels.com travelers also say the area is full of friendly people and has lots of nice beaches. It's also full of great shops and restaurants, so you can spend the afternoon having a wander.
You can take time to visit Upper Rock Nature Reserve during your travels to Gibraltar. Check out the shops and top-notch restaurants in this walkable area.